Testing, evaluation, and diagnostic equipment often produce vast amounts of digital data. The data set is often grouped around control words so that a specific type of data can be identified by its proximity to a control word. In order to sort through these vast amounts of data to select the data desired, data acquisition modules have been developed. Typically, these modules store a control word and a word count in registers. The data arrives serially. Control words in the data stream are compared to the control word register. Data words following each control word are counted. When the control word matches the control word register and the data word count matches the data word register, a capture command is sent to a data storage device indicating that the detected word should be captured and stored.
If words which occur in different locations, as measured by the control words, are to be captured, then additional data acquisition modules are used. Typically, the values in the registers are changed manually. If a large number of different data words occurring in different places in the data stream are to be captured, a similarly large number of data acquisition modules are required. This requires a large amount of hardware, space and expense. If different data words are to be captured for one task than for other tasks, then the values in the acquisition module registers must be changed. This is difficult and time consuming with manually set registers. Resetting the registers becomes increasingly difficult as the number of acquisition modules increases.